Dude made a working calculator that adds and substracts using:

- 610 magnetic switches
- 500 Wires
- 430 pistons
- 70 emitters
and others stuff...

Watch through the middle to see all the crazy wires required to build it.

The time to create this has to be days, not hours. Amazing things you can create in LittleBigPlanet. And this is only Beta!